The present invention relates to devices and methods of purification of oil from mechanical impurities in circulation lubrication systems, and can be used in gas, automobile and other industries.
A self-cleaning cartridge filter is disclosed for example in the inventor's certificate of the Soviet Union 886,940 and utilized for cleaning of natural and recirculating waters. This filter has a casing with an inlet pipe and an outlet pipe for liquids, filtering cartridges, brushes, a rotary drive for the brushes, and a pipe for purification withdrawal.
This filter has the disadvantage that the liquid purification can not be performed simultaneously with all filtering cartridges, since periodically one of the filtering cartridges must be turned off for washing.
Another filter for liquid purification is disclosed in the inventor's certificate of the Soviet Union No. 1,318,258. It has a housing, a cover with inlet and outlet openings, a filtering element mounted in the central part of the cover, and a magnetic trap. In order to increase the efficiency of purification and service life of the filter, the magnetic trap is formed as a permanent ring-shaped magnet arranged at the end sides of the pole shoes in form of disks of soft magnetic material. The disadvantage of this filter is that the magnetic cap is not cleaned. Moreover, the filter is characterized by a high metal consumption.
Another filter is disclosed in the inventor's certificate of the Soviet Union No. 891,120. It is used for liquid cooling of large electrical machines and includes a housing, inlet and outlet pipes for liquid, a magnetic guide with openings, and a magnetizing winding. The disadvantage of this construction is that it does not provide for a continuous liquid purification, since in order to clean the filter by a reverse washing, it is necessary to stop filtration. Moreover, mechanical impurities settle on the surface of the magnet, they are partially washed out by a liquid stream, and enter the system with pure liquid.
The closest filter to the present invention is the one which is used in cleaning of working liquids as disclosed for example in the publication "Purification of Working Liquids in Hydraulic Drives of Machine Tools", Moscow, "Machine Tools", 1976, page 247, FIG. 140. This filter separator has a housing with inlet and outlet pipes for oil, a filtering element and an immovable magnetic screen formed by magnetic rods. Dirty working liquid and oil are supplied through the inlet pipe into the housing of the filter separator, in which they are cleaned by the magnetic screen and then by the filtering element. The ferromagnetic particles are attracted by the screen and deposited on it, while non ferromagnetic particles are caught by the filtering element. Since the magnetic screen is immovable, the magnetic rods become covered with the ferromagnetic particles and the surface of the filtering element is clogged with non magnetic particles. This considerably reduces the inner-regeneration period of the filter-separator.